Currently when ISS has trash it sends it back in a Dragon module which has 10 m^3 of human rated volume. With the addition of some ports to allow long term parking of dragon modules and a space hatch that can be pressurized and depressurized it would be possible to have a “trash bag” module that isn’t even pressurized but is able to store trash and act as a vehicle for reentry and burn up powered by a single dragon module. You could almost imagine it being an actual trash bag that is multiple times thicker. It only has to last 24-36 hours in space just long enough to get the trash put inside it in a partial vacuum and then docked with the dragon module (likely via mechanical arm not docking) and then pulled into the Earth gravity well to burn up.
This could allow the dragon modules that are human rated and have already paid the $5,000-10,000/kg to be launched into LEO to be reused as space station storage and utility space. The vast majority of the cost of this plan is currently being spent.